import 'package:flutter/material.dart';
import 'package:english_words/english_words.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Welcome to Flutter',
//      theme: ThemeData(
//        // This is the theme of your application.
//        //
//        // Try running your application with "flutter run". You'll see the
//        // application has a blue toolbar. Then, without quitting the app, try
//        // changing the primarySwatch below to Colors.green and then invoke
//        // "hot reload" (press "r" in the console where you ran "flutter run",
//        // or simply save your changes to "hot reload" in a Flutter IDE).
//        // Notice that the counter didn't reset back to zero; the application
//        // is not restarted.
//        primarySwatch: Colors.blue,
//      ),
      debugShowCheckedModeBanner: false,
//      home: MyHomePage(title: 'wuzh'),
      initialRoute: '/', // 命名routes的/为首页
      routes: {
        '/': (context) => MyHomePage(title: 'Flutter Demo Home Page'),
        'no_result_or_args': (context) => NewRoute(),
        'routes_names_args': (context) => EchoRoute(),
        'get_result_or_args': (context) => TipRoute(text: ModalRoute.of(context).settings.arguments)
      },
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() => _counter++);
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      appBar: AppBar(
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: Text(widget.title),
      ),
      body: Center(
        // Center is a layout widget. It takes a single child and positions it
        // in the middle of the parent.
        child: Column(
          // Column is also a layout widget. It takes a list of children and
          // arranges them vertically. By default, it sizes itself to fit its
          // children horizontally, and tries to be as tall as its parent.
          //
          // Invoke "debug painting" (press "p" in the console, choose the
          // "Toggle Debug Paint" action from the Flutter Inspector in Android
          // Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
          // to see the wireframe for each widget.
          //
          // Column has various properties to control how it sizes itself and
          // how it positions its children. Here we use mainAxisAlignment to
          // center the children vertically; the main axis here is the vertical
          // axis because Columns are vertical (the cross axis would be
          // horizontal).
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.display1,
            ),
          ],
        ),
      ),
      bottomNavigationBar: BottomAppBar(
        shape: const CircularNotchedRectangle(),
        child: Container(height: 50.0,),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () => Navigator.of(context).pushNamed('get_result_or_args', arguments: WordPair.random()),
//        onPressed: () async {
//          var result = await Navigator.push(context, MaterialPageRoute(builder: (context) =>
////              NewRoute() // 下一页
//          TipRoute(text: "测试啦")
//          ));
//
//          print("返回值: $result");
//        },
        tooltip: 'Increment',
        child: Icon(Icons.navigate_next),

      ), // This trailing comma makes auto-formatting nicer for build methods.
      floatingActionButtonLocation: FloatingActionButtonLocation.centerDocked,

    );
  }

}

class NewRoute extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    return Scaffold(
      appBar: AppBar(
        title: Text("New Route"),
      ),
      body: Center(
        child: Text('This is new route'),
      ),
    );
  }
}

class TipRoute extends StatelessWidget {

  final String text;

  TipRoute({
    Key key,
    @required this.text
  }):super(key: key);

  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    return Scaffold(
      appBar: AppBar(
        title: Text('提示'),
      ),
      body: Padding(
        padding: EdgeInsets.all(18),
        child: Center(
          child: Column(
            children: <Widget>[
              Text(text),
              RaisedButton(onPressed: () => Navigator.pop(context, "我是返回值"),
              child: Text('返回!'),),
            ],
          ),
        ),
      ),
    );
  }
}

class EchoRoute extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    var args = ModalRoute.of(context).settings.arguments;
    print("args : $args");

    return Scaffold(
      appBar: AppBar(
        title: Text('提示'),
      ),
      body: Padding(
        padding: EdgeInsets.all(18),
        child: Center(
          child: Column(
            children: <Widget>[
              Text(args.toString()),
              RaisedButton(onPressed: () => Navigator.pop(context, "我是返回值"),
                child: Text('返回!'),),
            ],
          ),
        ),
      ),
    );

  }
}